The Craigentinny rail maintenance depot is located in the East of Edinburgh. With capacity for 176 rail vehicles, it is by far the largest depot in Scotland. It is responsible for the heavy rail maintenance and repair work required by Hitachi Rail’s East Coast main line trains.
We were commissioned by a long-standing client, steel fabricator Dixon Engineering Ltd in October 2023 to produce a land and measured building survey by laser scanning the depot’s maintenance building and yard. The aim was to create a high-definition 3D Revit model to import into the client’s building information modelling (BIM) software.
Equipment
Castle Surveys deployed a Scan Station P40, a high-definition laser scanning solution with a survey-grade dual-axis compensation, to complete a full travis closed-loop to known locations in the maintenance building and yard. This cutting-edge technology delivered the very highest quality 3D data and high dynamic range (HDR) imaging with an extremely fast scan rate of 1 million points to enable us to produce a realistic 3D colour point cloud.
Site Challenges
Our survey was part of a modernisation project that aimed to create a new platform with an overhead steel canopy to mirror the existing infrastructure in the depot. This meant two rail vehicles could be maintained simultaneously instead of just one, significantly improving maintenance productivity and costs.
Paul Jackson, Managing Director, Castle Surveys, explains, “As there were only ever two trains in the yard for each shift, one side of the depot has a steel canopy for overhead maintenance and the other side had none.
“The engineers had to switch the rail vehicles to use the single canopy to gain access to the roof of the train for maintenance, with the entire process taking around 30 minutes to complete. The aim was to design a new platform and steel canopy on both sides of the track preventing these time-consuming track changes.”
As the depot’s team operates 24 hours a day, we ensured that the laser scanning was completed in the most efficient time possible to minimise any disruption to operations. A major challenge for the survey was that there was only a slight 20mm step gap available between the new platform and the rail vehicles so the accuracy and precision of our surveying for the final design was paramount.
Solution
Our surveyor completed both a topographical survey of the entire site and a measured building survey, the resulting scans were used to developed a dimensionally accurate 3D model of the maintenance depot. This was used to complete the finished design, allowing Dixon Engineering to visualise the platform and surrounding building in granular detail, to ensure accurate positing of the new platform and steel maintenance canopy.
By using the latest surveying equipment, we were able to complete the detailed scanning required and provide excellent data in a single twelve-hour shift, while the resulting high-definition 3D Revit model was developed by our in-house team in just two weeks.
Setting-out
Once the design had been finalised our experienced engineers visited the site to complete the setting out process too where the dimensions and positions from the drawings are transferred onto the actual site. This ensured that the base plates for the steel canopy were aligned perfectly for the steel canopy so it didn’t deviate from the design.
“This project was about our commitment to accuracy and creating 2D drawings and a 3D Revit Model to provide a complete visual representation of the site to support our client in delivering a new steel canopy that would streamline maintenance at the depot for Hitachi Rail.” Said, Paul Jackson, Managing Director, Castle Surveys.
Summary
- Service: Topographical and Measured Building Survey
- Timescales: 2 weeks
- Equipment: A Leica P40 Scan Station
- Output: 2D CAD plans and a ‘digital twin’ 3D 300 Revit Model